Textile size



United States Patent TEXTILE SIZE John R. Fallon and Scott H. Foster, Springfield, Mass., assignors to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware.

No Drawing. Application October 28, 1954 Serial No. 465,444

Claims. (Cl. 260-23) This invention relates to the permanent sizing of textile Warp yarns. More particularly the invention relates to the permanent sizing of cellulosic filament .yarns with copolymers of vinyl acetate and crotonic acid.

It has long been a problem in the preparation of loom finished fabrics to find a permanent size which can be applied in the slashing operation prior to weaving. The problem has been most nearly solved by the development of ammonium salts of certain copolymers of vinyl acetate and crotonic acid as sizing agents. These salts can be applied from aqueous solutions to give a permanent size on' the yarns'which is resistant to water-spotting and which overcomes many of the other defects inherent in most permanent sizing materials. However, in the use of these salts in the conventional slashing operations, difficulty is experienced at the drying cans. If the cans are hot enough to provide adequate and efiicient drying the adhesion of the treated yarns to the drying cans is great enough so that many of the filaments in the yarn break. These broken filaments result in flufi balls which impede the weaving operation, and leave defects on the face of the cloth. If the temperature of the cans is reduced to prevent this breakage, then proper drying of the sized yarns is difiicult to obtain.

One object of this invention is to provide a new permanent sizing composition for cellulosic filament yarns.

2 formed in solution. Charge the resulting solution to a size box of a slasher. j r

Example 11 1.

. beam. The cans are heated at temperatures of l-200 F., 200 F., 200 F., 200 F., and 160 F. respectively; As the Wet yarns pass around the heated cans, there is substantially no adhesion of the yarn to the can surface and no evidence is seen of filament breakage. When the yarn so treated is woven as a warp yarn with an unsized filler yarn, fabrics are produced'which do not water spot and which may be subjected to mild laundering or dry cleaning without substantial removal of the sizing.

When a similar cellulose acetate filament yarn is sized with an aqueous solution of the same ammonium salt of vinyl acetate-crotonic acid copolymer without stearic acid modification, the wet yarn adheres to the heated cans to such an extent that considerable force is necessary to pull it therefrom. In the process of disengaging the wet yarn from the heated cans, numerous filament breaks are observed resulting in a yarn difiicult to weave.

Example III Prepare a clear solution of 8 parts of a copolymer of 95 mol percent vinyl acetate and 5 mol percentof crotonic acid and 0.2 part of stearic acid in 92 parts of'aqueous ammonia containing about 5 parts of ammonia. Con:

. sidered on a molar basis the amount of copolymer is about A further object is to modify sizing compositions consisting of ammonium salts of vinyl acetate-crotonic acid copolymers to prevent sticking to the drying cans in the slashing operation.

Another object is to modify ammonium salts of copolymers of vinyl acetate and crotonic acid so that they may be used as permanent sizes for cellulosic filament yarns without destroying the beneficial properties of said copolymer salts.

These and other objects are attained by preparing an aqueous sizing medium containing an ammonium. salt of a vinyl acetate-crotonic acid copolymer and a small amount of stearic acid or other fatty acid containing 12-20 carbon atoms.

The following examples are given in illustration and are not intended as limitations on the scope of this invention. Where parts are mentioned they are parts by weight.

Example 1 Prepare a sizing composition by dissolving 8 parts of a copolymer of 97 mol percent of vinyl acetate and 3 0.1 mol, the amount of crotonic acid present in said coremove the yarn from the can and there is substantially no evidence of broken filaments. Fabrics woven from this yarn do not water spot and may be printed without a removal of the size therefrom.

Attempts to obtain similar results by adding alkali metal salts of stearic acid to the copolymer salt solution, failed due to excessive foaming in the slasher bath and also due to increased sensitivity to water spotting. The use of less soluble stearates such as calcium or zinc stearate resulted in curds in the slasher bath, only a partial alleviation of the filament breakage problem and uneven appli cation of the size to the yarns.

The copolymers which are operative in this invention are copolymers of vinyl acetate and crotonic acid in which the vinyl acetate constitutes 99 mol percent of the copolymer and conversely the crotonic acid constitutes 5-1 mol percent of the copolymer. These copolymers are soluble in aqueous alkaline media and "are present therein in the form of their salts. The alkali metal and alkaline earth metal salts are not efiicient sizing agents and their use gives rise to many difliculties. However, the ammonium salts are excellent sizing agents which after application to the yarns followed by drying are not affected by water in the absence of alkali. It is the ammom'um salts which are the operative sizing agents of this invention.

Patented Nov. 4, 1958' Thefattyacids containing12-2O carbon atoms are suitable to obtain the improved processing conditions of this invention. Even the closely related alkali metal salts of the acids a're not suitable-to give the desired; results; The amount of acid should be from about0 .5% to about 3% by weight based on the Weight ofthe copolymer. Among the acids which may be used are lauric, palmitic, margaric, oleic, stearic, myristic, etc. acids and mixtures thereof. The sizing solutions of this invention are best prepared by dissolving the copolymer and the acid in a dilute solution of ammonia'in water, the amount of ammonia used being iniexcess of the amount required to form the salt of the'copolymer and as has previously been shown from a molar standpoint in the exemplary materials, see in particular ExampleiI, the excessforms the ammonia salts of the fatty acid as Well. In general the solutions should contain'from 110% byweight of the copolymer.

The compositionsof this invention are useful for thev sizingof cellulosic filamentary yarns such as cellulose acetate yarns and regenerated cellulose yarns. Since the size is a permanent size it is particularly useful for the treatment of colored yarns'with the result that the fabrics salt of a copolymer of vinyl acetate and crotonic acid and from 0.53.0% by weight of an ammonium salt of a fatty acid containing from 1220 carbon atoms based on the weight of the copolymer, the copolymer contain-' stearic acid present in an amount equal to 1.2% by weight i of the copolymer.

4. Cellulosic filamentary yarns sized with an ammonium salt of a copolymer of vinyl acetate and crotonic acid and from 0.53.0% by Weight of an ammonium salt of a fatty acid containing from l220 carbon atoms based on the weight of the copolymer, said copolymercontaining 95-99 mol percent of vinyl acetate and 5 to 1 mol.

percent of crotonic acid.

5. A sized yarn as in claim 4 wherein the vinyl ace-.-

tate content is 97 mol percent'and the crotonic acid is 3 mol percent of the copolymer and the acid is stearic acid in an amount equal to 1.2% by weight of the copolymer.

Wilson Nov. 6, 1956 

1. A COMPOSITION FOR SIZING CELLULOSE FILAMENTARY YARNS COMPRISING AN AQUEOUS AMMONIUM SOLUTION OF AMMONIUM SALT OF A COPOLYMER OF VINYL ACETATE AND CROTONIC ACID AND FROM 0.503.0% BY WEIGHT OF AN AMMONIUM SALT OF A FATTY ACID CONTAINING FROM 12-20 CARBON ATOMS BASED ON THE WEIGHT OF THE COPOLYMER, THE COPOLYMER CONTAINING FROM 95-99 MOL PERCENT OF VINYL ACETATE AND 5-1 MOL PERCENT OF CROTONIC ACID. 